I actually think that people who are beginner bloggers and people who have been blogging for a while would have slightly different reasons to stop blogging. For novices, I think that some sort of disinterest would be the primary reason. Since these people have never blogged before, the schedule may be a little demanding to start out, having to keep up with all the posts per week and all. Also, the blogger may realize that he or she is not as interested in the topic as once thought, or there just is not as much to write about as previously thought. For experienced bloggers, though, I don’t think that he or she would stop blogging and abandon the blog immediately; instead, I think that it would die out over time. If he or she enjoys blogging a great deal, then there will always be some time here and there to update the blog. After a while though, the blogger would probably feel some sort of “burnout” and not want to update the blog anymore, thereby making the blog dead.
If I were to ever have “blogger burnout” I would probably just back away for a while and not post on my blog. If I had a friend who had a great blog, but hasn’t updated in a while, I would offer words of encouragement to him or her and question as to why they are suddenly disinterested in keeping up with the blog. I would tell my friend that they have a terrific following and many people enjoy reading your blog and tell him or her that, if they really need to, take a few days or a week off and come back later when you feel more up to posting.